Electrolytic condenser



March 21, 1939. P. DUBILIER ELECTROLYTIC CONDENSER Filed April 18, 1956 INVENTOR. PhLlLp Dublier- O O O O O O OOOOO O O O O O O OOOOOOOOOOOOOOOOO G O O O ,O O 0 O WWU ATTORNEY.

Patented Mar. 21, 1939 PATENT OFFICE 2,151,504 mcraorir'rrc ooNnENsEa Philip Dubilier, New York,

Nova Electric Corporation, a corporation of New York N. Y., assigner to New York, N. Y.,

Application April 1s, 193s, serrano. 15,039 y l 4 Claims.

My invention relates to wet electrolytic condensers and more particularly relates to novel multi-section wet electrolytic condenser construction within'a common container.

There are many applications for high capacity multi-section condensers, particularly in the radio art, A multi-section condenser having a common negative terminal has heretofore been limited to the so-called dry electrolytic condensers where the positive foil sections were independently wound upon a common concentric condenser section. The advantages of wet electrolytccondensersover the dry electrolytic condensers reside in a longer life, lower power factor and no break-down or puncturing of the electrodes.

I contemplate a dual or multi-section wetl electrolytic condenser construction having a relatively large capacity and correspondingly small space. A common structural4 mounting assembly for the condenser results in a material economy in assemblingthe unit in a radio chassis. In accordance with my present invention, a corrugated, etched aluminum section comprises the positive electrode for each condenser section. A metallic spacer is used to isolate each condenser section to` eliminate intercapacity coupling between the condenser sections as well as increase their capacitance and reduce their power factor. The corrugated, etched condenser elements are provided with perforations or holes to further increase the section capacitance as will hereinafter be described.

It'is accordingly an object of my invention to provide novel'wet electrolytic multi-section condenser constructions.

Another object of my invention is to provide novel multi-section wet electrolytic condensers of increased capacitance per unit volume.

A further object of my invention is to provide novel multi-section wet electrolytic condensers free of intersection capacitance.

These and other objects of my invention will become apparent in the following. description in connection with the drawing in which:

Figure 1 is a partial cross-sectional elevation taken through a preferred construction of a dual electrolytic condenser in accordance with my present invention. f

Figure 2 is a cross-sectional view taken along 2-2 of Figure l illustrating the isolated dual section condenser construction.

Figure 3 shows a partial section of the perforated aluminum sheet comprising the condenser sections.

Figure 4 is a modincation illustrating a triple section wet electrolytic condenser.

Referring to Figure 1, metallic container III is preferably of cylindrical shape and' generally made of aluminum. The top section II has an annular shoulder I2 and contains a suitable breather construction which is not shown to permit escape of rapidly formed gases. Container III has an externally threaded boss I3 at the opposite end. Boss I3 is conically bored to receive an insulation stopper I4, ably a resilient rubber stopper which is press nt into boss I3 to suitably seal the liquid electrolyte I5 within container III. The ends I6 of boss I3 are pinched to ilrmly secure stopper I4 in position. A nut I1 is adaptedvto co-act with the threads I8 of boss I3 to suitably mount the electrolytic condenser upon a chassis in a weil known manner.

The container III forms a commonl condenser terminal and electrical connection to the common terminal is generally made through the chassis attachment construction including boss I3, nut I1 and the bottom of container I0. The positiveelements I3 and 2li of the dual condenser are vertically supported `by rods 2l a.nd..22.Y The liquid electrolyte I5 entirely surrounds condenser sections 'I9 and2ll and communicates between sections at the top portion I5 above metallic spacer 23. Electrolyte able liquid or viscous electrolyte for example a solution of borax and boric acid. Spacer .23 is a metallic partition, preferably welded at the ends 24 and 25A to container I0 as clearly illustrated in Figure 2 and is of the same material as container III.

Figure 2 illustrates the semi-circular corrugated form of condenser sections I9 and 20 of the dual condenser modification, on their supporting posts 2| and 22. The upper portions of rods 2l and 22 are attened to facilitate riveting together of the ends of the sections I9 and 20 thereon with rivets 26. The pitch and width of the corrugations of sheets I3 and 20 may be.used to provide a maximum non-interfering, exposed surface.

To provide a maximum capacitance per unit volume ofthe electrolytic condenser, the aluminum foil sections I9 and 2li are constructed in the following manner: The aluminum sheet 21 partially illustrated in Figure 3 is used to build up the positive sections I9 and 20 of the electrolytic condenser. The sheet is ilrst etched in a well known manner to increase the active surface of the section. Perforations 28 are then Member Il is prefer- I5 may be any suit- '3o made in the sheet for reasons to be explained hereinafter. The aluminum sheet 21 is then preformed in a manner well known to those skilled in the art. The next step is to corrugate the aluminum sheet in the manner illustrated in Figure 2. It is then formed in a semi-circular form and riveted to the supporting posts 2| and 22 as already described.

The-positive sections are inserted into the container Il) and the metallic rods 2| and 22 project through corresponding holes in the rubber stopper Il to serve as electrical connection terminals therefor. Lugs 29 and 3U are attached to the ends of terminal rods 2l and 22 for suitable connection thereto. The metallic spacer 23 has originally been welded or secured in position between the dual condenser sections I9 and 20. 'I'he bottom end 23 of shield 23 is preferably inserted in a corresponding groove in rubber stopper I4 although this expedient is not essential. l

Metallic shield 23 is at the same potential as the negative container IU and accordingly shields the individual capacitance sections I9 and 2li to avoid interelectrode capacitance therebetween as will be understood by those skilled in the art. Another advantage of the shield 23 is that it increases the capacitance of either condenser section due to the effective capacitive relation between the adjacent sections I9 and 20 and the plate 23. Provision of perforations 2B which incidentally have not been illustrated in Figures 1 and. 2 in order to simplify the drawing, permit capacitive interactions of the internal portion of the semi-circular sections I9 and 2|) with the surface of surrounding container I0 and in my present invention, also of shield 23 ina Well known manner. l

It will now be evident that the multi-section wet electrolytic condenser construction in accordance with my present invention provides for a maximum capacitance within a given volume or space and avoids intercapacitive'action between the sections to accordingly electrically isolate them except for the common negative terminal. The provision. of corrugated, perforated, etched aluminum foil permits a maximum capacitiveV etliciency for a given condenser section volume.

Figure 4 illustrates a modification of the hereinabove described dual condenser sections comprising three sections 31,32 and 33 corresponding to the dualsections I9 and 20. Sections 3|- 32-33 are similarly mounted on connection posts 34, 35 and 36 which communicate to the exterior of the container I for terminalconnections to the respective sections as will now be understood. Suitable metal spacers 23a are welded into container ID and as illustrated in Figure 4 may be readily constructed by bending one sheet 31 at its center at an angle of 120 and welding another sheet thereto at 38. It is to be understood that more than three sections may be built up into a single condenser container in a manner similar to the already described moditlcations.

Although I have illustrated a preferred construction for the novel multi-section wet electrolytic condensers, it will be evident to those skilled in the art, that modications may be made that come within the broader spirit and scope of my present invention, for example, the electrolyte may be viscous instead of fluid, and that the spacers 23 may be of insulation material or even omitted, and accordingly, I do not intend to be limited except as set forth in the following claims.

Iclaim:

1. A multi-section electrolytic' condenser comprising a metallic container having an opening centrally thereof substantially narrower indiameter than the diameter of the container and adapted for single-opening panel mounting, an electrolyte in the container, a stopper for said opening, a pluralityof condenser electrodes, individual closely spaced lead-in rodsfor said elec- "trodes anchored in said stopper and projecting into said container, said electrodes Ahaving crosssections in the form of a sector of a circle, and being secured to said rods along sector axis portions thereof to form individual centrally supported electrolytic sections coacting with the common potential metallic container.

2. A multi-section electrolytic condenser comprising a metallic container having an opening centrally thereof substantially narrower in diameter than the diameter of the container and adapted for single-opening panelmounting, an electrolyte in the container, a stopper for said opening, a plurality of condenser electrodes, individual closely spaced lead-in rods for said electrodes anchored in said stopper and projecting into said container, said electrodes having crosssections in the form of a sector of a circle and being symmetrically arranged about the axis of said container, said sector-shaped electrodes `be ing secured to said rods along sector axis por,- tions thereof to form individual centrally supported electrolytic sections coacting with the common potential metallic container.

3. A multi-section electrolytic condenser comprising a metallic container having an opening centrally thereof substantially narrower in diameter than the diameter of the container and adapted for single-opening panel mounting, an electrolyte in the container, a stopper for said opening, a plurality of condenser electrodes. individual closely spaced lead-in rods for said electrodes anchored in said stopper and projecting into said container, said electrodes being secured to said rods at commonly opposing surface portions oi.' the electrodes on the outer periphery thereof and being symmetrically arranged about the axis of said container to form individual centrally supported electrolytic sections coacting with the common potential metallic container.

4. A multi-section electrolytic condenser com- Y prising a metallic container having an opening centrally thereof substantially narrower in diameter than the diameter of the container and adapted for singleopening panel mounting, an electrolyte in the container, a stopper for said opening, a plurality of condenser electrodes, individual closely spaced lead-in rods for said electrodes anchored in said stopper and projecting into said container, said electrodes being tubular and having cross-sections in the form of al sector of a circle and being symmetrically arranged about the axis of said container, the sector angles of said electrodes totalling within three-hundred and sixty degrees, said sectorshaped electrodesv being secured to said rods along sector axis portions thereof to form individual centrally supported electrolytic sections coacting with the common kpotential metallic container.

PIHLIP DUBILIER. 

